Flapper valve assemblies are commonly deployed onboard aircraft to regulate the flow of a fluid; e.g., as a specific example, a flapper valve assembly may be utilized as a check valve to prevent back airflow within an aircraft cabin air conditioning system. A generalized flapper valve assembly includes a flowbody housing (referred to herein simply as a “flowbody”), a flow passage formed through the flowbody, a flapper valve element (e.g., a rectangular or circular plate), and various other structural elements (e.g., a hard stop feature, a spring or other damping member, etc.). The flapper valve element is hingedly mounted to the flowbody and is movable between a fully open position, a closed position, and various intermediate positions. The flowbody is formed to include a flat plate portion, which accommodates the flapper valve element in the fully open position (commonly referred to as a “mailbox” configuration). More specifically, the flapper valve element is hingedly mounted to the flowbody proximate the leading or upstream edge of the flat plate portion. When transitioning into the fully open position, the flapper valve element rotates into a position adjacent the flat plate portion and is effectively removed from the flow path. By removing the flapper valve element from the flow path in this manner, fluid flow through the flowbody is optimized and valve element flutter is reduced or eliminated. In addition, when the flapper valve assembly is deployed onboard an aircraft, removal of the flapper valve element from the flow path helps to minimize the accumulation of ice within the flowbody during flight.
When deployed onboard an aircraft, it is desirable for a flapper valve assembly to be relatively lightweight. At the same time, it is desirable for the flapper valve assembly to be capable of withstanding significant pressure loading conditions without premature fatigue and the possible development of leakage paths. In general, the weight of a valve assembly can be minimized by reducing flowbody wall thickness; however, reducing flowbody wall thickness results in a corresponding reduction in the pressure loading capabilities of the valve assembly. In conventional flapper valve assemblies of the type described above, the flat plate portion of the flowbody has poor structural stiffness and consequently tends to experience relatively large deflection (bulges outward) when subjected to high pressure loading conditions. Deflection of the flowbody's flat plate portion becomes increasingly problematic as the scale of the flapper valve assembly increases and, therefore, as the surface area of the flat plate area increases. Furthermore, corners are inherently formed in the transitional area between the flowbody's flat plate portion and the remainder of the flowbody, which is typically characterized by a generally annular or arcuate cross-sectional geometry. While adding a certain amount of structural stiffness, these corners produce undesirable stress concentrations in certain regions of the flowbody during pressure loading, which, in turn, can result in premature fatigue of the flapper valve assembly.
Considering the above, there exists an ongoing need to provide embodiments of a lightweight flapper valve assembly that includes a flat plate portion resistive to physical deflection and that provides a more uniform stress distribution during high pressure loading conditions. It is also desirable to provide embodiments of a method for manufacturing such a lightweight flapper valve assembly. Other desirable features and characteristics of the present invention will become apparent from the subsequent Detailed Description and the appended claims, taken in conjunction with the accompanying Drawings and this Background.